Re: [PATCH v3 2/6] rtc: rzn1: Add new RTC driver

[Geert Uytterhoeven <geert@linux-m68k.org>]

Hi Miquel,

On Fri, Apr 29, 2022 at 12:46 PM Miquel Raynal
<miquel.raynal@bootlin.com> wrote:
> From: Michel Pollet <michel.pollet@bp.renesas.com>
>
> Add a basic RTC driver for the RZ/N1.
>
> Signed-off-by: Michel Pollet <michel.pollet@bp.renesas.com>
> Co-developed-by: Miquel Raynal <miquel.raynal@bootlin.com>
> Signed-off-by: Miquel Raynal <miquel.raynal@bootlin.com>

Thanks for your patch!

> --- /dev/null
> +++ b/drivers/rtc/rtc-rzn1.c
> @@ -0,0 +1,246 @@
> +// SPDX-License-Identifier: GPL-2.0+
> +/*
> + * Renesas RZN1 Real Time Clock interface for Linux

RZ/N1

> +static int rzn1_rtc_probe(struct platform_device *pdev)
> +{
> +       struct rzn1_rtc *rtc;
> +       int ret;
> +
> +       rtc = devm_kzalloc(&pdev->dev, sizeof(*rtc), GFP_KERNEL);
> +       if (!rtc)
> +               return -ENOMEM;
> +
> +       platform_set_drvdata(pdev, rtc);
> +
> +       rtc->base = devm_platform_ioremap_resource(pdev, 0);
> +       if (IS_ERR(rtc->base))
> +               return dev_err_probe(&pdev->dev, PTR_ERR(rtc->base), "Missing reg\n");
> +
> +       rtc->rtcdev = devm_rtc_allocate_device(&pdev->dev);
> +       if (IS_ERR(rtc->rtcdev))
> +               return PTR_ERR(rtc);
> +
> +       rtc->rtcdev->range_min = RTC_TIMESTAMP_BEGIN_2000;
> +       rtc->rtcdev->range_max = RTC_TIMESTAMP_END_2099;
> +       rtc->rtcdev->ops = &rzn1_rtc_ops;
> +       clear_bit(RTC_FEATURE_ALARM, rtc->rtcdev->features);
> +       clear_bit(RTC_FEATURE_UPDATE_INTERRUPT, rtc->rtcdev->features);
> +
> +       pm_runtime_enable(&pdev->dev);
> +       pm_runtime_get_sync(&pdev->dev);

While this call cannot really fail on this platform, you may want to
call pm_runtime_resume_and_get() instead, and check its return
value (else the janitors will make that change later ;-)

> +
> +       /*
> +        * Ensure the clock counter is enabled.
> +        * Set 24-hour mode and possible oscillator offset compensation in SUBU mode.
> +        */
> +       writel(RZN1_RTC_CTL0_CE | RZN1_RTC_CTL0_AMPM | RZN1_RTC_CTL0_SLSB_SUBU,
> +              rtc->base + RZN1_RTC_CTL0);
> +
> +       /* Disable all interrupts */
> +       writel(0, rtc->base + RZN1_RTC_CTL1);
> +
> +       ret = devm_rtc_register_device(rtc->rtcdev);
> +       if (ret)
> +               goto dis_runtime_pm;
> +
> +       return 0;
> +
> +dis_runtime_pm:
> +       pm_runtime_put_sync(&pdev->dev);

pm_runtime_put() should be fine, no need for the synchronous version.

> +       pm_runtime_disable(&pdev->dev);
> +
> +       return ret;
> +}
> +
> +static int rzn1_rtc_remove(struct platform_device *pdev)
> +{
> +       pm_runtime_put_sync(&pdev->dev);

pm_runtime_put().

> +       pm_runtime_disable(&pdev->dev);
> +
> +       return 0;
> +}

Gr{oetje,eeting}s,

                        Geert

--
Geert Uytterhoeven -- There's lots of Linux beyond ia32 -- geert@linux-m68k.org

In personal conversations with technical people, I call myself a hacker. But
when I'm talking to journalists I just say "programmer" or something like that.
                                -- Linus Torvalds